aboutsummaryrefslogtreecommitdiffstats
path: root/security/tomoyo/file.c
blob: cef685415df1c587f86d19c4f83e9bb1664d8f3e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
/*
 * security/tomoyo/file.c
 *
 * Pathname restriction functions.
 *
 * Copyright (C) 2005-2010  NTT DATA CORPORATION
 */

#include "common.h"
#include <linux/slab.h>

/* Keyword array for operations with one pathname. */
static const char *tomoyo_path_keyword[TOMOYO_MAX_PATH_OPERATION] = {
	[TOMOYO_TYPE_READ_WRITE] = "read/write",
	[TOMOYO_TYPE_EXECUTE]    = "execute",
	[TOMOYO_TYPE_READ]       = "read",
	[TOMOYO_TYPE_WRITE]      = "write",
	[TOMOYO_TYPE_UNLINK]     = "unlink",
	[TOMOYO_TYPE_RMDIR]      = "rmdir",
	[TOMOYO_TYPE_TRUNCATE]   = "truncate",
	[TOMOYO_TYPE_SYMLINK]    = "symlink",
	[TOMOYO_TYPE_REWRITE]    = "rewrite",
	[TOMOYO_TYPE_CHROOT]     = "chroot",
	[TOMOYO_TYPE_UMOUNT]     = "unmount",
};

/* Keyword array for operations with one pathname and three numbers. */
static const char *tomoyo_path_number3_keyword
[TOMOYO_MAX_PATH_NUMBER3_OPERATION] = {
	[TOMOYO_TYPE_MKBLOCK]    = "mkblock",
	[TOMOYO_TYPE_MKCHAR]     = "mkchar",
};

/* Keyword array for operations with two pathnames. */
static const char *tomoyo_path2_keyword[TOMOYO_MAX_PATH2_OPERATION] = {
	[TOMOYO_TYPE_LINK]       = "link",
	[TOMOYO_TYPE_RENAME]     = "rename",
	[TOMOYO_TYPE_PIVOT_ROOT] = "pivot_root",
};

/* Keyword array for operations with one pathname and one number. */
static const char *tomoyo_path_number_keyword
[TOMOYO_MAX_PATH_NUMBER_OPERATION] = {
	[TOMOYO_TYPE_CREATE]     = "create",
	[TOMOYO_TYPE_MKDIR]      = "mkdir",
	[TOMOYO_TYPE_MKFIFO]     = "mkfifo",
	[TOMOYO_TYPE_MKSOCK]     = "mksock",
	[TOMOYO_TYPE_IOCTL]      = "ioctl",
	[TOMOYO_TYPE_CHMOD]      = "chmod",
	[TOMOYO_TYPE_CHOWN]      = "chown",
	[TOMOYO_TYPE_CHGRP]      = "chgrp",
};

void tomoyo_put_name_union(struct tomoyo_name_union *ptr)
{
	if (!ptr)
		return;
	if (ptr->is_group)
		tomoyo_put_path_group(ptr->group);
	else
		tomoyo_put_name(ptr->filename);
}

bool tomoyo_compare_name_union(const struct tomoyo_path_info *name,
			       const struct tomoyo_name_union *ptr)
{
	if (ptr->is_group)
		return tomoyo_path_matches_group(name, ptr->group, 1);
	return tomoyo_path_matches_pattern(name, ptr->filename);
}

static bool tomoyo_compare_name_union_pattern(const struct tomoyo_path_info
					      *name,
					      const struct tomoyo_name_union
					      *ptr, const bool may_use_pattern)
{
	if (ptr->is_group)
		return tomoyo_path_matches_group(name, ptr->group,
						 may_use_pattern);
	if (may_use_pattern || !ptr->filename->is_patterned)
		return tomoyo_path_matches_pattern(name, ptr->filename);
	return false;
}

void tomoyo_put_number_union(struct tomoyo_number_union *ptr)
{
	if (ptr && ptr->is_group)
		tomoyo_put_number_group(ptr->group);
}

bool tomoyo_compare_number_union(const unsigned long value,
				 const struct tomoyo_number_union *ptr)
{
	if (ptr->is_group)
		return tomoyo_number_matches_group(value, value, ptr->group);
	return value >= ptr->values[0] && value <= ptr->values[1];
}

/**
 * tomoyo_path2keyword - Get the name of single path operation.
 *
 * @operation: Type of operation.
 *
 * Returns the name of single path operation.
 */
const char *tomoyo_path2keyword(const u8 operation)
{
	return (operation < TOMOYO_MAX_PATH_OPERATION)
		? tomoyo_path_keyword[operation] : NULL;
}

/**
 * tomoyo_path_number32keyword - Get the name of path/number/number/number operations.
 *
 * @operation: Type of operation.
 *
 * Returns the name of path/number/number/number operation.
 */
const char *tomoyo_path_number32keyword(const u8 operation)
{
	return (operation < TOMOYO_MAX_PATH_NUMBER3_OPERATION)
		? tomoyo_path_number3_keyword[operation] : NULL;
}

/**
 * tomoyo_path22keyword - Get the name of double path operation.
 *
 * @operation: Type of operation.
 *
 * Returns the name of double path operation.
 */
const char *tomoyo_path22keyword(const u8 operation)
{
	return (operation < TOMOYO_MAX_PATH2_OPERATION)
		? tomoyo_path2_keyword[operation] : NULL;
}

/**
 * tomoyo_path_number2keyword - Get the name of path/number operations.
 *
 * @operation: Type of operation.
 *
 * Returns the name of path/number operation.
 */
const char *tomoyo_path_number2keyword(const u8 operation)
{
	return (operation < TOMOYO_MAX_PATH_NUMBER_OPERATION)
		? tomoyo_path_number_keyword[operation] : NULL;
}

static void tomoyo_add_slash(struct tomoyo_path_info *buf)
{
	if (buf->is_dir)
		return;
	/*
	 * This is OK because tomoyo_encode() reserves space for appending "/".
	 */
	strcat((char *) buf->name, "/");
	tomoyo_fill_path_info(buf);
}

/**
 * tomoyo_strendswith - Check whether the token ends with the given token.
 *
 * @name: The token to check.
 * @tail: The token to find.
 *
 * Returns true if @name ends with @tail, false otherwise.
 */
static bool tomoyo_strendswith(const char *name, const char *tail)
{
	int len;

	if (!name || !tail)
		return false;
	len = strlen(name) - strlen(tail);
	return len >= 0 && !strcmp(name + len, tail);
}

/**
 * tomoyo_get_realpath - Get realpath.
 *
 * @buf:  Pointer to "struct tomoyo_path_info".
 * @path: Pointer to "struct path".
 *
 * Returns true on success, false otherwise.
 */
static bool tomoyo_get_realpath(struct tomoyo_path_info *buf, struct path *path)
{
	buf->name = tomoyo_realpath_from_path(path);
	if (buf->name) {
		tomoyo_fill_path_info(buf);
		return true;
	}
        return false;
}

static int tomoyo_update_path2_acl(const u8 type, const char *filename1,
				   const char *filename2,
				   struct tomoyo_domain_info *const domain,
				   const bool is_delete);
static int tomoyo_update_path_acl(const u8 type, const char *filename,
				  struct tomoyo_domain_info *const domain,
				  const bool is_delete);

/*
 * tomoyo_globally_readable_list is used for holding list of pathnames which
 * are by default allowed to be open()ed for reading by any process.
 *
 * An entry is added by
 *
 * # echo 'allow_read /lib/libc-2.5.so' > \
 *                               /sys/kernel/security/tomoyo/exception_policy
 *
 * and is deleted by
 *
 * # echo 'delete allow_read /lib/libc-2.5.so' > \
 *                               /sys/kernel/security/tomoyo/exception_policy
 *
 * and all entries are retrieved by
 *
 * # grep ^allow_read /sys/kernel/security/tomoyo/exception_policy
 *
 * In the example above, any process is allowed to
 * open("/lib/libc-2.5.so", O_RDONLY).
 * One exception is, if the domain which current process belongs to is marked
 * as "ignore_global_allow_read", current process can't do so unless explicitly
 * given "allow_read /lib/libc-2.5.so" to the domain which current process
 * belongs to.
 */
LIST_HEAD(tomoyo_globally_readable_list);

/**
 * tomoyo_update_globally_readable_entry - Update "struct tomoyo_globally_readable_file_entry" list.
 *
 * @filename:  Filename unconditionally permitted to open() for reading.
 * @is_delete: True if it is a delete request.
 *
 * Returns 0 on success, negative value otherwise.
 *
 * Caller holds tomoyo_read_lock().
 */
static int tomoyo_update_globally_readable_entry(const char *filename,
						 const bool is_delete)
{
	struct tomoyo_globally_readable_file_entry *ptr;
	struct tomoyo_globally_readable_file_entry e = { };
	int error = is_delete ? -ENOENT : -ENOMEM;

	if (!tomoyo_is_correct_path(filename, 1, 0, -1))
		return -EINVAL;
	e.filename = tomoyo_get_name(filename);
	if (!e.filename)
		return -ENOMEM;
	if (mutex_lock_interruptible(&tomoyo_policy_lock))
		goto out;
	list_for_each_entry_rcu(ptr, &tomoyo_globally_readable_list, list) {
		if (ptr->filename != e.filename)
			continue;
		ptr->is_deleted = is_delete;
		error = 0;
		break;
	}
	if (!is_delete && error) {
		struct tomoyo_globally_readable_file_entry *entry =
			tomoyo_commit_ok(&e, sizeof(e));
		if (entry) {
			list_add_tail_rcu(&entry->list,
					  &tomoyo_globally_readable_list);
			error = 0;
		}
	}
	mutex_unlock(&tomoyo_policy_lock);
 out:
	tomoyo_put_name(e.filename);
	return error;
}

/**
 * tomoyo_is_globally_readable_file - Check if the file is unconditionnaly permitted to be open()ed for reading.
 *
 * @filename: The filename to check.
 *
 * Returns true if any domain can open @filename for reading, false otherwise.
 *
 * Caller holds tomoyo_read_lock().
 */
static bool tomoyo_is_globally_readable_file(const struct tomoyo_path_info *
					     filename)
{
	struct tomoyo_globally_readable_file_entry *ptr;
	bool found = false;

	list_for_each_entry_rcu(ptr, &tomoyo_globally_readable_list, list) {
		if (!ptr->is_deleted &&
		    tomoyo_path_matches_pattern(filename, ptr->filename)) {
			found = true;
			break;
		}
	}
	return found;
}

/**
 * tomoyo_write_globally_readable_policy - Write "struct tomoyo_globally_readable_file_entry" list.
 *
 * @data:      String to parse.
 * @is_delete: True if it is a delete request.
 *
 * Returns 0 on success, negative value otherwise.
 *
 * Caller holds tomoyo_read_lock().
 */
int tomoyo_write_globally_readable_policy(char *data, const bool is_delete)
{
	return tomoyo_update_globally_readable_entry(data, is_delete);
}

/**
 * tomoyo_read_globally_readable_policy - Read "struct tomoyo_globally_readable_file_entry" list.
 *
 * @head: Pointer to "struct tomoyo_io_buffer".
 *
 * Returns true on success, false otherwise.
 *
 * Caller holds tomoyo_read_lock().
 */
bool tomoyo_read_globally_readable_policy(struct tomoyo_io_buffer *head)
{
	struct list_head *pos;
	bool done = true;

	list_for_each_cookie(pos, head->read_var2,
			     &tomoyo_globally_readable_list) {
		struct tomoyo_globally_readable_file_entry *ptr;
		ptr = list_entry(pos,
				 struct tomoyo_globally_readable_file_entry,
				 list);
		if (ptr->is_deleted)
			continue;
		done = tomoyo_io_printf(head, TOMOYO_KEYWORD_ALLOW_READ "%s\n",
					ptr->filename->name);
		if (!done)
			break;
	}
	return done;
}

/* tomoyo_pattern_list is used for holding list of pathnames which are used for
 * converting pathnames to pathname patterns during learning mode.
 *
 * An entry is added by
 *
 * # echo 'file_pattern /proc/\$/mounts' > \
 *                             /sys/kernel/security/tomoyo/exception_policy
 *
 * and is deleted by
 *
 * # echo 'delete file_pattern /proc/\$/mounts' > \
 *                             /sys/kernel/security/tomoyo/exception_policy
 *
 * and all entries are retrieved by
 *
 * # grep ^file_pattern /sys/kernel/security/tomoyo/exception_policy
 *
 * In the example above, if a process which belongs to a domain which is in
 * learning mode requested open("/proc/1/mounts", O_RDONLY),
 * "allow_read /proc/\$/mounts" is automatically added to the domain which that
 * process belongs to.
 *
 * It is not a desirable behavior that we have to use /proc/\$/ instead of
 * /proc/self/ when current process needs to access only current process's
 * information. As of now, LSM version of TOMOYO is using __d_path() for
 * calculating pathname. Non LSM version of TOMOYO is using its own function
 * which pretends as if /proc/self/ is not a symlink; so that we can forbid
 * current process from accessing other process's information.
 */
LIST_HEAD(tomoyo_pattern_list);

/**
 * tomoyo_update_file_pattern_entry - Update "struct tomoyo_pattern_entry" list.
 *
 * @pattern:   Pathname pattern.
 * @is_delete: True if it is a delete request.
 *
 * Returns 0 on success, negative value otherwise.
 *
 * Caller holds tomoyo_read_lock().
 */
static int tomoyo_update_file_pattern_entry(const char *pattern,
					    const bool is_delete)
{
	struct tomoyo_pattern_entry *ptr;
	struct tomoyo_pattern_entry e = { .pattern = tomoyo_get_name(pattern) };
	int error = is_delete ? -ENOENT : -ENOMEM;

	if (!e.pattern)
		return error;
	if (!e.pattern->is_patterned)
		goto out;
	if (mutex_lock_interruptible(&tomoyo_policy_lock))
		goto out;
	list_for_each_entry_rcu(ptr, &tomoyo_pattern_list, list) {
		if (e.pattern != ptr->pattern)
			continue;
		ptr->is_deleted = is_delete;
		error = 0;
		break;
	}
	if (!is_delete && error) {
		struct tomoyo_pattern_entry *entry =
			tomoyo_commit_ok(&e, sizeof(e));
		if (entry) {
			list_add_tail_rcu(&entry->list, &tomoyo_pattern_list);
			error = 0;
		}
	}
	mutex_unlock(&tomoyo_policy_lock);
 out:
	tomoyo_put_name(e.pattern);
	return error;
}

/**
 * tomoyo_file_pattern - Get patterned pathname.
 *
 * @filename: The filename to find patterned pathname.
 *
 * Returns pointer to pathname pattern if matched, @filename otherwise.
 *
 * Caller holds tomoyo_read_lock().
 */
const char *tomoyo_file_pattern(const struct tomoyo_path_info *filename)
{
	struct tomoyo_pattern_entry *ptr;
	const struct tomoyo_path_info *pattern = NULL;

	list_for_each_entry_rcu(ptr, &tomoyo_pattern_list, list) {
		if (ptr->is_deleted)
			continue;
		if (!tomoyo_path_matches_pattern(filename, ptr->pattern))
			continue;
		pattern = ptr->pattern;
		if (tomoyo_strendswith(pattern->name, "/\\*")) {
			/* Do nothing. Try to find the better match. */
		} else {
			/* This would be the better match. Use this. */
			break;
		}
	}
	if (pattern)
		filename = pattern;
	return filename->name;
}

/**
 * tomoyo_write_pattern_policy - Write "struct tomoyo_pattern_entry" list.
 *
 * @data:      String to parse.
 * @is_delete: True if it is a delete request.
 *
 * Returns 0 on success, negative value otherwise.
 *
 * Caller holds tomoyo_read_lock().
 */
int tomoyo_write_pattern_policy(char *data, const bool is_delete)
{
	return tomoyo_update_file_pattern_entry(data, is_delete);
}

/**
 * tomoyo_read_file_pattern - Read "struct tomoyo_pattern_entry" list.
 *
 * @head: Pointer to "struct tomoyo_io_buffer".
 *
 * Returns true on success, false otherwise.
 *
 * Caller holds tomoyo_read_lock().
 */
bool tomoyo_read_file_pattern(struct tomoyo_io_buffer *head)
{
	struct list_head *pos;
	bool done = true;

	list_for_each_cookie(pos, head->read_var2, &tomoyo_pattern_list) {
		struct tomoyo_pattern_entry *ptr;
		ptr = list_entry(pos, struct tomoyo_pattern_entry, list);
		if (ptr->is_deleted)
			continue;
		done = tomoyo_io_printf(head, TOMOYO_KEYWORD_FILE_PATTERN
					"%s\n", ptr->pattern->name);
		if (!done)
			break;
	}
	return done;
}

/*
 * tomoyo_no_rewrite_list is used for holding list of pathnames which are by
 * default forbidden to modify already written content of a file.
 *
 * An entry is added by
 *
 * # echo 'deny_rewrite /var/log/messages' > \
 *                              /sys/kernel/security/tomoyo/exception_policy
 *
 * and is deleted by
 *
 * # echo 'delete deny_rewrite /var/log/messages' > \
 *                              /sys/kernel/security/tomoyo/exception_policy
 *
 * and all entries are retrieved by
 *
 * # grep ^deny_rewrite /sys/kernel/security/tomoyo/exception_policy
 *
 * In the example above, if a process requested to rewrite /var/log/messages ,
 * the process can't rewrite unless the domain which that process belongs to
 * has "allow_rewrite /var/log/messages" entry.
 *
 * It is not a desirable behavior that we have to add "\040(deleted)" suffix
 * when we want to allow rewriting already unlink()ed file. As of now,
 * LSM version of TOMOYO is using __d_path() for calculating pathname.
 * Non LSM version of TOMOYO is using its own function which doesn't append
 * " (deleted)" suffix if the file is already unlink()ed; so that we don't
 * need to worry whether the file is already unlink()ed or not.
 */
LIST_HEAD(tomoyo_no_rewrite_list);

/**
 * tomoyo_update_no_rewrite_entry - Update "struct tomoyo_no_rewrite_entry" list.
 *
 * @pattern:   Pathname pattern that are not rewritable by default.
 * @is_delete: True if it is a delete request.
 *
 * Returns 0 on success, negative value otherwise.
 *
 * Caller holds tomoyo_read_lock().
 */
static int tomoyo_update_no_rewrite_entry(const char *pattern,
					  const bool is_delete)
{
	struct tomoyo_no_rewrite_entry *ptr;
	struct tomoyo_no_rewrite_entry e = { };
	int error = is_delete ? -ENOENT : -ENOMEM;

	if (!tomoyo_is_correct_path(pattern, 0, 0, 0))
		return -EINVAL;
	e.pattern = tomoyo_get_name(pattern);
	if (!e.pattern)
		return error;
	if (mutex_lock_interruptible(&tomoyo_policy_lock))
		goto out;
	list_for_each_entry_rcu(ptr, &tomoyo_no_rewrite_list, list) {
		if (ptr->pattern != e.pattern)
			continue;
		ptr->is_deleted = is_delete;
		error = 0;
		break;
	}
	if (!is_delete && error) {
		struct tomoyo_no_rewrite_entry *entry =
			tomoyo_commit_ok(&e, sizeof(e));
		if (entry) {
			list_add_tail_rcu(&entry->list,
					  &tomoyo_no_rewrite_list);
			error = 0;
		}
	}
	mutex_unlock(&tomoyo_policy_lock);
 out:
	tomoyo_put_name(e.pattern);
	return error;
}

/**
 * tomoyo_is_no_rewrite_file - Check if the given pathname is not permitted to be rewrited.
 *
 * @filename: Filename to check.
 *
 * Returns true if @filename is specified by "deny_rewrite" directive,
 * false otherwise.
 *
 * Caller holds tomoyo_read_lock().
 */
static bool tomoyo_is_no_rewrite_file(const struct tomoyo_path_info *filename)
{
	struct tomoyo_no_rewrite_entry *ptr;
	bool found = false;

	list_for_each_entry_rcu(ptr, &tomoyo_no_rewrite_list, list) {
		if (ptr->is_deleted)
			continue;
		if (!tomoyo_path_matches_pattern(filename, ptr->pattern))
			continue;
		found = true;
		break;
	}
	return found;
}

/**
 * tomoyo_write_no_rewrite_policy - Write "struct tomoyo_no_rewrite_entry" list.
 *
 * @data:      String to parse.
 * @is_delete: True if it is a delete request.
 *
 * Returns 0 on success, negative value otherwise.
 *
 * Caller holds tomoyo_read_lock().
 */
int tomoyo_write_no_rewrite_policy(char *data, const bool is_delete)
{
	return tomoyo_update_no_rewrite_entry(data, is_delete);
}

/**
 * tomoyo_read_no_rewrite_policy - Read "struct tomoyo_no_rewrite_entry" list.
 *
 * @head: Pointer to "struct tomoyo_io_buffer".
 *
 * Returns true on success, false otherwise.
 *
 * Caller holds tomoyo_read_lock().
 */
bool tomoyo_read_no_rewrite_policy(struct tomoyo_io_buffer *head)
{
	struct list_head *pos;
	bool done = true;

	list_for_each_cookie(pos, head->read_var2, &tomoyo_no_rewrite_list) {
		struct tomoyo_no_rewrite_entry *ptr;
		ptr = list_entry(pos, struct tomoyo_no_rewrite_entry, list);
		if (ptr->is_deleted)
			continue;
		done = tomoyo_io_printf(head, TOMOYO_KEYWORD_DENY_REWRITE
					"%s\n", ptr->pattern->name);
		if (!done)
			break;
	}
	return done;
}

/**
 * tomoyo_update_file_acl - Update file's read/write/execute ACL.
 *
 * @perm:      Permission (between 1 to 7).
 * @filename:  Filename.
 * @domain:    Pointer to "struct tomoyo_domain_info".
 * @is_delete: True if it is a delete request.
 *
 * Returns 0 on success, negative value otherwise.
 *
 * This is legacy support interface for older policy syntax.
 * Current policy syntax uses "allow_read/write" instead of "6",
 * "allow_read" instead of "4", "allow_write" instead of "2",
 * "allow_execute" instead of "1".
 *
 * Caller holds tomoyo_read_lock().
 */
static int tomoyo_update_file_acl(u8 perm, const char *filename,
				  struct tomoyo_domain_info * const domain,
				  const bool is_delete)
{
	if (perm > 7 || !perm) {
		printk(KERN_DEBUG "%s: Invalid permission '%d %s'\n",
		       __func__, perm, filename);
		return -EINVAL;
	}
	if (filename[0] != '@' && tomoyo_strendswith(filename, "/"))
		/*
		 * Only 'allow_mkdir' and 'allow_rmdir' are valid for
		 * directory permissions.
		 */
		return 0;
	if (perm & 4)
		tomoyo_update_path_acl(TOMOYO_TYPE_READ, filename, domain,
				       is_delete);
	if (perm & 2)
		tomoyo_update_path_acl(TOMOYO_TYPE_WRITE, filename, domain,
				       is_delete);
	if (perm & 1)
		tomoyo_update_path_acl(TOMOYO_TYPE_EXECUTE, filename, domain,
				       is_delete);
	return 0;
}

/**
 * tomoyo_path_acl - Check permission for single path operation.
 *
 * @r:               Pointer to "struct tomoyo_request_info".
 * @filename:        Filename to check.
 * @perm:            Permission.
 * @may_use_pattern: True if patterned ACL is permitted.
 *
 * Returns 0 on success, -EPERM otherwise.
 *
 * Caller holds tomoyo_read_lock().
 */
static int tomoyo_path_acl(const struct tomoyo_request_info *r,
			   const struct tomoyo_path_info *filename,
			   const u32 perm, const bool may_use_pattern)
{
	struct tomoyo_domain_info *domain = r->domain;
	struct tomoyo_acl_info *ptr;
	int error = -EPERM;

	list_for_each_entry_rcu(ptr, &domain->acl_info_list, list) {
		struct tomoyo_path_acl *acl;
		if (ptr->type != TOMOYO_TYPE_PATH_ACL)
			continue;
		acl = container_of(ptr, struct tomoyo_path_acl, head);
		if (!(acl->perm & perm) ||
		    !tomoyo_compare_name_union_pattern(filename, &acl->name,
                                                       may_use_pattern))
			continue;
		error = 0;
		break;
	}
	return error;
}

/**
 * tomoyo_file_perm - Check permission for opening files.
 *
 * @r:         Pointer to "struct tomoyo_request_info".
 * @filename:  Filename to check.
 * @mode:      Mode ("read" or "write" or "read/write" or "execute").
 *
 * Returns 0 on success, negative value otherwise.
 *
 * Caller holds tomoyo_read_lock().
 */
static int tomoyo_file_perm(struct tomoyo_request_info *r,
			    const struct tomoyo_path_info *filename,
			    const u8 mode)
{
	const char *msg = "<unknown>";
	int error = 0;
	u32 perm = 0;

	if (!filename)
		return 0;

	if (mode == 6) {
		msg = tomoyo_path2keyword(TOMOYO_TYPE_READ_WRITE);
		perm = 1 << TOMOYO_TYPE_READ_WRITE;
	} else if (mode == 4) {
		msg = tomoyo_path2keyword(TOMOYO_TYPE_READ);
		perm = 1 << TOMOYO_TYPE_READ;
	} else if (mode == 2) {
		msg = tomoyo_path2keyword(TOMOYO_TYPE_WRITE);
		perm = 1 << TOMOYO_TYPE_WRITE;
	} else if (mode == 1) {
		msg = tomoyo_path2keyword(TOMOYO_TYPE_EXECUTE);
		perm = 1 << TOMOYO_TYPE_EXECUTE;
	} else
		BUG();
	do {
		error = tomoyo_path_acl(r, filename, perm, mode != 1);
		if (error && mode == 4 && !r->domain->ignore_global_allow_read
		    && tomoyo_is_globally_readable_file(filename))
			error = 0;
		if (!error)
			break;
		tomoyo_warn_log(r, "%s %s", msg, filename->name);
		error = tomoyo_supervisor(r, "allow_%s %s\n", msg,
					  mode == 1 ? filename->name :
					  tomoyo_file_pattern(filename));
		/*
                 * Do not retry for execute request, for alias may have
		 * changed.
                 */
	} while (error == TOMOYO_RETRY_REQUEST && mode != 1);
	if (r->mode != TOMOYO_CONFIG_ENFORCING)
		error = 0;
	return error;
}

/**
 * tomoyo_update_path_acl - Update "struct tomoyo_path_acl" list.
 *
 * @type:      Type of operation.
 * @filename:  Filename.
 * @domain:    Pointer to "struct tomoyo_domain_info".
 * @is_delete: True if it is a delete request.
 *
 * Returns 0 on success, negative value otherwise.
 *
 * Caller holds tomoyo_read_lock().
 */
static int tomoyo_update_path_acl(const u8 type, const char *filename,
				  struct tomoyo_domain_info *const domain,
				  const bool is_delete)
{
	static const u16 tomoyo_rw_mask =
		(1 << TOMOYO_TYPE_READ) | (1 << TOMOYO_TYPE_WRITE);
	const u16 perm = 1 << type;
	struct tomoyo_acl_info *ptr;
	struct tomoyo_path_acl e = {
		.head.type = TOMOYO_TYPE_PATH_ACL,
		.perm = perm
	};
	int error = is_delete ? -ENOENT : -ENOMEM;

	if (type == TOMOYO_TYPE_READ_WRITE)
		e.perm |= tomoyo_rw_mask;
	if (!domain)
		return -EINVAL;
	if (!tomoyo_parse_name_union(filename, &e.name))
		return -EINVAL;
	if (mutex_lock_interruptible(&tomoyo_policy_lock))
		goto out;
	list_for_each_entry_rcu(ptr, &domain->acl_info_list, list) {
		struct tomoyo_path_acl *acl =
			container_of(ptr, struct tomoyo_path_acl, head);
		if (!tomoyo_is_same_path_acl(acl, &e))
			continue;
		if (is_delete) {
			acl->perm &= ~perm;
			if ((acl->perm & tomoyo_rw_mask) != tomoyo_rw_mask)
				acl->perm &= ~(1 << TOMOYO_TYPE_READ_WRITE);
			else if (!(acl->perm & (1 << TOMOYO_TYPE_READ_WRITE)))
				acl->perm &= ~tomoyo_rw_mask;
		} else {
			acl->perm |= perm;
			if ((acl->perm & tomoyo_rw_mask) == tomoyo_rw_mask)
				acl->perm |= 1 << TOMOYO_TYPE_READ_WRITE;
			else if (acl->perm & (1 << TOMOYO_TYPE_READ_WRITE))
				acl->perm |= tomoyo_rw_mask;
		}
		error = 0;
		break;
	}
	if (!is_delete && error) {
		struct tomoyo_path_acl *entry =
			tomoyo_commit_ok(&e, sizeof(e));
		if (entry) {
			list_add_tail_rcu(&entry->head.list,
					  &domain->acl_info_list);
			error = 0;
		}
	}
	mutex_unlock(&tomoyo_policy_lock);
 out:
	tomoyo_put_name_union(&e.name);
	return error;
}

/**
 * tomoyo_update_path_number3_acl - Update "struct tomoyo_path_number3_acl" list.
 *
 * @type:      Type of operation.
 * @filename:  Filename.
 * @mode:      Create mode.
 * @major:     Device major number.
 * @minor:     Device minor number.
 * @domain:    Pointer to "struct tomoyo_domain_info".
 * @is_delete: True if it is a delete request.
 *
 * Returns 0 on success, negative value otherwise.
 */
static inline int tomoyo_update_path_number3_acl(const u8 type,
						 const char *filename,
						 char *mode,
						 char *major, char *minor,
						 struct tomoyo_domain_info *
						 const domain,
						 const bool is_delete)
{
	const u8 perm = 1 << type;
	struct tomoyo_acl_info *ptr;
	struct tomoyo_path_number3_acl e = {
		.head.type = TOMOYO_TYPE_PATH_NUMBER3_ACL,
		.perm = perm
	};
	int error = is_delete ? -ENOENT : -ENOMEM;
	if (!tomoyo_parse_name_union(filename, &e.name) ||
	    !tomoyo_parse_number_union(mode, &e.mode) ||
	    !tomoyo_parse_number_union(major, &e.major) ||
	    !tomoyo_parse_number_union(minor, &e.minor))
		goto out;
	if (mutex_lock_interruptible(&tomoyo_policy_lock))
		goto out;
	list_for_each_entry_rcu(ptr, &domain->acl_info_list, list) {
		struct tomoyo_path_number3_acl *acl =
			container_of(ptr, struct tomoyo_path_number3_acl, head);
		if (!tomoyo_is_same_path_number3_acl(acl, &e))
			continue;
		if (is_delete)
			acl->perm &= ~perm;
		else
			acl->perm |= perm;
		error = 0;
		break;
	}
	if (!is_delete && error) {
		struct tomoyo_path_number3_acl *entry =
			tomoyo_commit_ok(&e, sizeof(e));
		if (entry) {
			list_add_tail_rcu(&entry->head.list,
					  &domain->acl_info_list);
			error = 0;
		}
	}
	mutex_unlock(&tomoyo_policy_lock);
 out:
	tomoyo_put_name_union(&e.name);
	tomoyo_put_number_union(&e.mode);
	tomoyo_put_number_union(&e.major);
	tomoyo_put_number_union(&e.minor);
	return error;
}

/**
 * tomoyo_update_path2_acl - Update "struct tomoyo_path2_acl" list.
 *
 * @type:      Type of operation.
 * @filename1: First filename.
 * @filename2: Second filename.
 * @domain:    Pointer to "struct tomoyo_domain_info".
 * @is_delete: True if it is a delete request.
 *
 * Returns 0 on success, negative value otherwise.
 *
 * Caller holds tomoyo_read_lock().
 */
static int tomoyo_update_path2_acl(const u8 type, const char *filename1,
				   const char *filename2,
				   struct tomoyo_domain_info *const domain,
				   const bool is_delete)
{
	const u8 perm = 1 << type;
	struct tomoyo_path2_acl e = {
		.head.type = TOMOYO_TYPE_PATH2_ACL,
		.perm = perm
	};
	struct tomoyo_acl_info *ptr;
	int error = is_delete ? -ENOENT : -ENOMEM;

	if (!domain)
		return -EINVAL;
	if (!tomoyo_parse_name_union(filename1, &e.name1) ||
	    !tomoyo_parse_name_union(filename2, &e.name2))
		goto out;
	if (mutex_lock_interruptible(&tomoyo_policy_lock))
		goto out;
	list_for_each_entry_rcu(ptr, &domain->acl_info_list, list) {
		struct tomoyo_path2_acl *acl =
			container_of(ptr, struct tomoyo_path2_acl, head);
		if (!tomoyo_is_same_path2_acl(acl, &e))
			continue;
		if (is_delete)
			acl->perm &= ~perm;
		else
			acl->perm |= perm;
		error = 0;
		break;
	}
	if (!is_delete && error) {
		struct tomoyo_path2_acl *entry =
			tomoyo_commit_ok(&e, sizeof(e));
		if (entry) {
			list_add_tail_rcu(&entry->head.list,
					  &domain->acl_info_list);
			error = 0;
		}
	}
	mutex_unlock(&tomoyo_policy_lock);
 out:
	tomoyo_put_name_union(&e.name1);
	tomoyo_put_name_union(&e.name2);
	return error;
}

/**
 * tomoyo_path_number3_acl - Check permission for path/number/number/number operation.
 *
 * @r:        Pointer to "struct tomoyo_request_info".
 * @filename: Filename to check.
 * @perm:     Permission.
 * @mode:     Create mode.
 * @major:    Device major number.
 * @minor:    Device minor number.
 *
 * Returns 0 on success, -EPERM otherwise.
 *
 * Caller holds tomoyo_read_lock().
 */
static int tomoyo_path_number3_acl(struct tomoyo_request_info *r,
				   const struct tomoyo_path_info *filename,
				   const u16 perm, const unsigned int mode,
				   const unsigned int major,
				   const unsigned int minor)
{
	struct tomoyo_domain_info *domain = r->domain;
	struct tomoyo_acl_info *ptr;
	int error = -EPERM;
	list_for_each_entry_rcu(ptr, &domain->acl_info_list, list) {
		struct tomoyo_path_number3_acl *acl;
		if (ptr->type != TOMOYO_TYPE_PATH_NUMBER3_ACL)
			continue;
		acl = container_of(ptr, struct tomoyo_path_number3_acl, head);
		if (!tomoyo_compare_number_union(mode, &acl->mode))
			continue;
		if (!tomoyo_compare_number_union(major, &acl->major))
			continue;
		if (!tomoyo_compare_number_union(minor, &acl->minor))
			continue;
		if (!(acl->perm & perm))
			continue;
		if (!tomoyo_compare_name_union(filename, &acl->name))
			continue;
		error = 0;
		break;
	}
	return error;
}

/**
 * tomoyo_path2_acl - Check permission for double path operation.
 *
 * @r:         Pointer to "struct tomoyo_request_info".
 * @type:      Type of operation.
 * @filename1: First filename to check.
 * @filename2: Second filename to check.
 *
 * Returns 0 on success, -EPERM otherwise.
 *
 * Caller holds tomoyo_read_lock().
 */
static int tomoyo_path2_acl(const struct tomoyo_request_info *r, const u8 type,
			    const struct tomoyo_path_info *filename1,
			    const struct tomoyo_path_info *filename2)
{
	const struct tomoyo_domain_info *domain = r->domain;
	struct tomoyo_acl_info *ptr;
	const u8 perm = 1 << type;
	int error = -EPERM;

	list_for_each_entry_rcu(ptr, &domain->acl_info_list, list) {
		struct tomoyo_path2_acl *acl;
		if (ptr->type != TOMOYO_TYPE_PATH2_ACL)
			continue;
		acl = container_of(ptr, struct tomoyo_path2_acl, head);
		if (!(acl->perm & perm))
			continue;
		if (!tomoyo_compare_name_union(filename1, &acl->name1))
			continue;
		if (!tomoyo_compare_name_union(filename2, &acl->name2))
			continue;
		error = 0;
		break;
	}
	return error;
}

/**
 * tomoyo_path_permission - Check permission for single path operation.
 *
 * @r:         Pointer to "struct tomoyo_request_info".
 * @operation: Type of operation.
 * @filename:  Filename to check.
 *
 * Returns 0 on success, negative value otherwise.
 *
 * Caller holds tomoyo_read_lock().
 */
static int tomoyo_path_permission(struct tomoyo_request_info *r, u8 operation,
				  const struct tomoyo_path_info *filename)
{
	const char *msg;
	int error;

 next:
	do {
		error = tomoyo_path_acl(r, filename, 1 << operation, 1);
		if (!error)
			break;
		msg = tomoyo_path2keyword(operation);
		tomoyo_warn_log(r, "%s %s", msg, filename->name);
		error = tomoyo_supervisor(r, "allow_%s %s\n", msg,
					  tomoyo_file_pattern(filename));
	} while (error == TOMOYO_RETRY_REQUEST);
	if (r->mode != TOMOYO_CONFIG_ENFORCING)
		error = 0;
	/*
	 * Since "allow_truncate" doesn't imply "allow_rewrite" permission,
	 * we need to check "allow_rewrite" permission if the filename is
	 * specified by "deny_rewrite" keyword.
	 */
	if (!error && operation == TOMOYO_TYPE_TRUNCATE &&
	    tomoyo_is_no_rewrite_file(filename)) {
		operation = TOMOYO_TYPE_REWRITE;
		goto next;
	}
	return error;
}

/**
 * tomoyo_path_number_acl - Check permission for ioctl/chmod/chown/chgrp operation.
 *
 * @r:        Pointer to "struct tomoyo_request_info".
 * @type:     Operation.
 * @filename: Filename to check.
 * @number:   Number.
 *
 * Returns 0 on success, -EPERM otherwise.
 *
 * Caller holds tomoyo_read_lock().
 */
static int tomoyo_path_number_acl(struct tomoyo_request_info *r, const u8 type,
				  const struct tomoyo_path_info *filename,
				  const unsigned long number)
{
	struct tomoyo_domain_info *domain = r->domain;
	struct tomoyo_acl_info *ptr;
	const u8 perm = 1 << type;
	int error = -EPERM;
	list_for_each_entry_rcu(ptr, &domain->acl_info_list, list) {
		struct tomoyo_path_number_acl *acl;
		if (ptr->type != TOMOYO_TYPE_PATH_NUMBER_ACL)
			continue;
		acl = container_of(ptr, struct tomoyo_path_number_acl,
				   head);
		if (!(acl->perm & perm) ||
		    !tomoyo_compare_number_union(number, &acl->number) ||
		    !tomoyo_compare_name_union(filename, &acl->name))
			continue;
		error = 0;
		break;
	}
	return error;
}

/**
 * tomoyo_update_path_number_acl - Update ioctl/chmod/chown/chgrp ACL.
 *
 * @type:      Type of operation.
 * @filename:  Filename.
 * @number:    Number.
 * @domain:    Pointer to "struct tomoyo_domain_info".
 * @is_delete: True if it is a delete request.
 *
 * Returns 0 on success, negative value otherwise.
 */
static inline int tomoyo_update_path_number_acl(const u8 type,
						const char *filename,
						char *number,
						struct tomoyo_domain_info *
						const domain,
						const bool is_delete)
{
	const u8 perm = 1 << type;
	struct tomoyo_acl_info *ptr;
	struct tomoyo_path_number_acl e = {
		.head.type = TOMOYO_TYPE_PATH_NUMBER_ACL,
		.perm = perm
	};
	int error = is_delete ? -ENOENT : -ENOMEM;
	if (!domain)
		return -EINVAL;
	if (!tomoyo_parse_name_union(filename, &e.name))
		return -EINVAL;
	if (!tomoyo_parse_number_union(number, &e.number))
		goto out;
	if (mutex_lock_interruptible(&tomoyo_policy_lock))
		goto out;
	list_for_each_entry_rcu(ptr, &domain->acl_info_list, list) {
		struct tomoyo_path_number_acl *acl =
			container_of(ptr, struct tomoyo_path_number_acl, head);
		if (!tomoyo_is_same_path_number_acl(acl, &e))
			continue;
		if (is_delete)
			acl->perm &= ~perm;
		else
			acl->perm |= perm;
		error = 0;
		break;
	}
	if (!is_delete && error) {
		struct tomoyo_path_number_acl *entry =
			tomoyo_commit_ok(&e, sizeof(e));
		if (entry) {
			list_add_tail_rcu(&entry->head.list,
					  &domain->acl_info_list);
			error = 0;
		}
	}
	mutex_unlock(&tomoyo_policy_lock);
 out:
	tomoyo_put_name_union(&e.name);
	tomoyo_put_number_union(&e.number);
	return error;
}

/**
 * tomoyo_path_number_perm2 - Check permission for "create", "mkdir", "mkfifo", "mksock", "ioctl", "chmod", "chown", "chgrp".
 *
 * @r:        Pointer to "strct tomoyo_request_info".
 * @filename: Filename to check.
 * @number:   Number.
 *
 * Returns 0 on success, negative value otherwise.
 *
 * Caller holds tomoyo_read_lock().
 */
static int tomoyo_path_number_perm2(struct tomoyo_request_info *r,
				    const u8 type,
				    const struct tomoyo_path_info *filename,
				    const unsigned long number)
{
	char buffer[64];
	int error;
	u8 radix;
	const char *msg;

	if (!filename)
		return 0;
	switch (type) {
	case TOMOYO_TYPE_CREATE:
	case TOMOYO_TYPE_MKDIR:
	case TOMOYO_TYPE_MKFIFO:
	case TOMOYO_TYPE_MKSOCK:
	case TOMOYO_TYPE_CHMOD:
		radix = TOMOYO_VALUE_TYPE_OCTAL;
		break;
	case TOMOYO_TYPE_IOCTL:
		radix = TOMOYO_VALUE_TYPE_HEXADECIMAL;
		break;
	default:
		radix = TOMOYO_VALUE_TYPE_DECIMAL;
		break;
	}
	tomoyo_print_ulong(buffer, sizeof(buffer), number, radix);
	do {
		error = tomoyo_path_number_acl(r, type, filename, number);
		if (!error)
			break;
		msg = tomoyo_path_number2keyword(type);
		tomoyo_warn_log(r, "%s %s %s", msg, filename->name, buffer);
		error = tomoyo_supervisor(r, "allow_%s %s %s\n", msg,
					  tomoyo_file_pattern(filename),
					  buffer);
	} while (error == TOMOYO_RETRY_REQUEST);
	if (r->mode != TOMOYO_CONFIG_ENFORCING)
		error = 0;
	return error;
}

/**
 * tomoyo_path_number_perm - Check permission for "create", "mkdir", "mkfifo", "mksock", "ioctl", "chmod", "chown", "chgrp".
 *
 * @type:   Type of operation.
 * @path:   Pointer to "struct path".
 * @number: Number.
 *
 * Returns 0 on success, negative value otherwise.
 */
int tomoyo_path_number_perm(const u8 type, struct path *path,
			    unsigned long number)
{
	struct tomoyo_request_info r;
	int error = -ENOMEM;
	struct tomoyo_path_info buf;
	int idx;

	if (tomoyo_init_request_info(&r, NULL) == TOMOYO_CONFIG_DISABLED ||
	    !path->mnt || !path->dentry)
		return 0;
	idx = tomoyo_read_lock();
	if (!tomoyo_get_realpath(&buf, path))
		goto out;
	if (type == TOMOYO_TYPE_MKDIR)
		tomoyo_add_slash(&buf);
	error = tomoyo_path_number_perm2(&r, type, &buf, number);
 out:
	kfree(buf.name);
	tomoyo_read_unlock(idx);
	if (r.mode != TOMOYO_CONFIG_ENFORCING)
		error = 0;
	return error;
}

/**
 * tomoyo_check_exec_perm - Check permission for "execute".
 *
 * @domain:   Pointer to "struct tomoyo_domain_info".
 * @filename: Check permission for "execute".
 *
 * Returns 0 on success, negativevalue otherwise.
 *
 * Caller holds tomoyo_read_lock().
 */
int tomoyo_check_exec_perm(struct tomoyo_domain_info *domain,
			   const struct tomoyo_path_info *filename)
{
	struct tomoyo_request_info r;

	if (tomoyo_init_request_info(&r, NULL) == TOMOYO_CONFIG_DISABLED)
		return 0;
	return tomoyo_file_perm(&r, filename, 1);
}

/**
 * tomoyo_check_open_permission - Check permission for "read" and "write".
 *
 * @domain: Pointer to "struct tomoyo_domain_info".
 * @path:   Pointer to "struct path".
 * @flag:   Flags for open().
 *
 * Returns 0 on success, negative value otherwise.
 */
int tomoyo_check_open_permission(struct tomoyo_domain_info *domain,
				 struct path *path, const int flag)
{
	const u8 acc_mode = ACC_MODE(flag);
	int error = -ENOMEM;
	struct tomoyo_path_info buf;
	struct tomoyo_request_info r;
	int idx;

	if (tomoyo_init_request_info(&r, domain) == TOMOYO_CONFIG_DISABLED ||
	    !path->mnt)
		return 0;
	if (acc_mode == 0)
		return 0;
	if (path->dentry->d_inode && S_ISDIR(path->dentry->d_inode->i_mode))
		/*
		 * I don't check directories here because mkdir() and rmdir()
		 * don't call me.
		 */
		return 0;
	idx = tomoyo_read_lock();
	if (!tomoyo_get_realpath(&buf, path))
		goto out;
	error = 0;
	/*
	 * If the filename is specified by "deny_rewrite" keyword,
	 * we need to check "allow_rewrite" permission when the filename is not
	 * opened for append mode or the filename is truncated at open time.
	 */
	if ((acc_mode & MAY_WRITE) &&
	    ((flag & O_TRUNC) || !(flag & O_APPEND)) &&
	    (tomoyo_is_no_rewrite_file(&buf))) {
		error = tomoyo_path_permission(&r, TOMOYO_TYPE_REWRITE, &buf);
	}
	if (!error)
		error = tomoyo_file_perm(&r, &buf, acc_mode);
	if (!error && (flag & O_TRUNC))
		error = tomoyo_path_permission(&r, TOMOYO_TYPE_TRUNCATE, &buf);
 out:
	kfree(buf.name);
	tomoyo_read_unlock(idx);
	if (r.mode != TOMOYO_CONFIG_ENFORCING)
		error = 0;
	return error;
}

/**
 * tomoyo_path_perm - Check permission for "unlink", "rmdir", "truncate", "symlink", "rewrite", "chroot" and "unmount".
 *
 * @operation: Type of operation.
 * @path:      Pointer to "struct path".
 *
 * Returns 0 on success, negative value otherwise.
 */
int tomoyo_path_perm(const u8 operation, struct path *path)
{
	int error = -ENOMEM;
	struct tomoyo_path_info buf;
	struct tomoyo_request_info r;
	int idx;

	if (tomoyo_init_request_info(&r, NULL) == TOMOYO_CONFIG_DISABLED ||
	    !path->mnt)
		return 0;
	idx = tomoyo_read_lock();
	if (!tomoyo_get_realpath(&buf, path))
		goto out;
	switch (operation) {
	case TOMOYO_TYPE_REWRITE:
		if (!tomoyo_is_no_rewrite_file(&buf)) {
			error = 0;
			goto out;
		}
		break;
	case TOMOYO_TYPE_RMDIR:
	case TOMOYO_TYPE_CHROOT:
		tomoyo_add_slash(&buf);
		break;
	}
	error = tomoyo_path_permission(&r, operation, &buf);
 out:
	kfree(buf.name);
	tomoyo_read_unlock(idx);
	if (r.mode != TOMOYO_CONFIG_ENFORCING)
		error = 0;
	return error;
}

/**
 * tomoyo_path_number3_perm2 - Check permission for path/number/number/number operation.
 *
 * @r:         Pointer to "struct tomoyo_request_info".
 * @operation: Type of operation.
 * @filename:  Filename to check.
 * @mode:      Create mode.
 * @dev:       Device number.
 *
 * Returns 0 on success, negative value otherwise.
 *
 * Caller holds tomoyo_read_lock().
 */
static int tomoyo_path_number3_perm2(struct tomoyo_request_info *r,
				     const u8 operation,
				     const struct tomoyo_path_info *filename,
				     const unsigned int mode,
				     const unsigned int dev)
{
	int error;
	const char *msg;
	const unsigned int major = MAJOR(dev);
	const unsigned int minor = MINOR(dev);

	do {
		error = tomoyo_path_number3_acl(r, filename, 1 << operation,
						mode, major, minor);
		if (!error)
			break;
		msg = tomoyo_path_number32keyword(operation);
		tomoyo_warn_log(r, "%s %s 0%o %u %u", msg, filename->name,
				mode, major, minor);
		error = tomoyo_supervisor(r, "allow_%s %s 0%o %u %u\n", msg,
					  tomoyo_file_pattern(filename), mode,
					  major, minor);
	} while (error == TOMOYO_RETRY_REQUEST);
        if (r->mode != TOMOYO_CONFIG_ENFORCING)
		error = 0;
	return error;
}

/**
 * tomoyo_path_number3_perm - Check permission for "mkblock" and "mkchar".
 *
 * @operation: Type of operation. (TOMOYO_TYPE_MKCHAR or TOMOYO_TYPE_MKBLOCK)
 * @path:      Pointer to "struct path".
 * @mode:      Create mode.
 * @dev:       Device number.
 *
 * Returns 0 on success, negative value otherwise.
 */
int tomoyo_path_number3_perm(const u8 operation, struct path *path,
			     const unsigned int mode, unsigned int dev)
{
	struct tomoyo_request_info r;
	int error = -ENOMEM;
	struct tomoyo_path_info buf;
	int idx;

	if (tomoyo_init_request_info(&r, NULL) == TOMOYO_CONFIG_DISABLED ||
	    !path->mnt)
		return 0;
	idx = tomoyo_read_lock();
	error = -ENOMEM;
	if (tomoyo_get_realpath(&buf, path)) {
		error = tomoyo_path_number3_perm2(&r, operation, &buf, mode,
						  new_decode_dev(dev));
		kfree(buf.name);
	}
	tomoyo_read_unlock(idx);
	if (r.mode != TOMOYO_CONFIG_ENFORCING)
		error = 0;
	return error;
}

/**
 * tomoyo_path2_perm - Check permission for "rename", "link" and "pivot_root".
 *
 * @operation: Type of operation.
 * @path1:      Pointer to "struct path".
 * @path2:      Pointer to "struct path".
 *
 * Returns 0 on success, negative value otherwise.
 */
int tomoyo_path2_perm(const u8 operation, struct path *path1,
		      struct path *path2)
{
	int error = -ENOMEM;
	const char *msg;
	struct tomoyo_path_info buf1;
	struct tomoyo_path_info buf2;
	struct tomoyo_request_info r;
	int idx;

	if (tomoyo_init_request_info(&r, NULL) == TOMOYO_CONFIG_DISABLED ||
	    !path1->mnt || !path2->mnt)
		return 0;
	buf1.name = NULL;
	buf2.name = NULL;
	idx = tomoyo_read_lock();
	if (!tomoyo_get_realpath(&buf1, path1) ||
	    !tomoyo_get_realpath(&buf2, path2))
		goto out;
	{
		struct dentry *dentry = path1->dentry;
		if (dentry->d_inode && S_ISDIR(dentry->d_inode->i_mode)) {
			tomoyo_add_slash(&buf1);
			tomoyo_add_slash(&buf2);
		}
	}
	do {
		error = tomoyo_path2_acl(&r, operation, &buf1, &buf2);
		if (!error)
			break;
		msg = tomoyo_path22keyword(operation);
		tomoyo_warn_log(&r, "%s %s %s", msg, buf1.name, buf2.name);
		error = tomoyo_supervisor(&r, "allow_%s %s %s\n", msg,
					  tomoyo_file_pattern(&buf1),
					  tomoyo_file_pattern(&buf2));
        } while (error == TOMOYO_RETRY_REQUEST);
 out:
	kfree(buf1.name);
	kfree(buf2.name);
	tomoyo_read_unlock(idx);
	if (r.mode != TOMOYO_CONFIG_ENFORCING)
		error = 0;
	return error;
}

/**
 * tomoyo_write_file_policy - Update file related list.
 *
 * @data:      String to parse.
 * @domain:    Pointer to "struct tomoyo_domain_info".
 * @is_delete: True if it is a delete request.
 *
 * Returns 0 on success, negative value otherwise.
 *
 * Caller holds tomoyo_read_lock().
 */
int tomoyo_write_file_policy(char *data, struct tomoyo_domain_info *domain,
			     const bool is_delete)
{
	char *w[5];
	u8 type;
	if (!tomoyo_tokenize(data, w, sizeof(w)) || !w[1][0])
		return -EINVAL;
	if (strncmp(w[0], "allow_", 6)) {
		unsigned int perm;
		if (sscanf(w[0], "%u", &perm) == 1)
			return tomoyo_update_file_acl((u8) perm, w[1], domain,
						      is_delete);
		goto out;
	}
	w[0] += 6;
	for (type = 0; type < TOMOYO_MAX_PATH_OPERATION; type++) {
		if (strcmp(w[0], tomoyo_path_keyword[type]))
			continue;
		return tomoyo_update_path_acl(type, w[1], domain, is_delete);
	}
	if (!w[2][0])
		goto out;
	for (type = 0; type < TOMOYO_MAX_PATH2_OPERATION; type++) {
		if (strcmp(w[0], tomoyo_path2_keyword[type]))
			continue;
		return tomoyo_update_path2_acl(type, w[1], w[2], domain,
					       is_delete);
	}
	for (type = 0; type < TOMOYO_MAX_PATH_NUMBER_OPERATION; type++) {
		if (strcmp(w[0], tomoyo_path_number_keyword[type]))
			continue;
		return tomoyo_update_path_number_acl(type, w[1], w[2], domain,
						     is_delete);
	}
	if (!w[3][0] || !w[4][0])
		goto out;
	for (type = 0; type < TOMOYO_MAX_PATH_NUMBER3_OPERATION; type++) {
		if (strcmp(w[0], tomoyo_path_number3_keyword[type]))
			continue;
		return tomoyo_update_path_number3_acl(type, w[1], w[2], w[3],
						      w[4], domain, is_delete);
	}
 out:
	return -EINVAL;
}